High frequency copper wire

[thaithanh]

Please tell me ,where can i buy it !

 

[Nigel Goodwin]

It's called 'Litz wire', what do you want it for?.

 

[JimB]

Try these guys:

https://www.wires.co.uk/index.html

JimB

 

[thaithanh]

thank for help !
i need it for transformer of the ultrasonic cleaning machine
and i have prolem with Ultrasonic transduce,I cant undertand how to drive it .please tell me about it .

 

[Nigel Goodwin]

I doubt you need it for an ultrasonic cleaner, they work at a fairly low frequency - if used the reason would be for flexibility, not it's HF capability.

 

[thaithanh]

it work in 20kHz-40khz,in high votage so cant use normal copper wire

 

[Hero999]

That's not high frequency, copper wire will do fine.

What voltage are you using?

As far as the dialectric strength is concerned, it's only the maximum voltage between neighbouring windings that's important.

 

[thaithanh]

about 600 v
i try with normal copper wire it very hot
in the machine i repair it use lizt wire

 

[Andrew Leigh]

Hi

The purpose of litz wire is to reduce the heating created by the skin effect, where as the frequency increases so the current flow moves to the outside of the conductor creating an uneven distibution of current across the area of the conductor hence the heating effect.

So in effect copper wire is not "high frequency" but the arrangement of independently insulated fine wire is suitable for high frequency applications. At the frequencies you are mentioning there will be heating and that is why they have used Litz wire. It is very expensive.

Cheers
Andrew

 

[Hero999]

about 600 v

Is that the total voltage or maximum voltage between adjacent turns?

For example if I could wind ten layers each consisting of 10 turns and the total voltage is 1kV the maximum voltage between one winding and the next would only be 100V which would be fine for enameled coper wire.

I doubt you've got 600V per layer so I'm guessing it's the total voltage.

i try with normal copper wire it very hot
in the machine i repair it use lizt wire

What's the current and how thick is the wire?

Are you sure the core isn't saturating?

Another alternative is to use two or more bifilar windings in parallel which is often done in high power SMPes.

 

[thaithanh]

this my transformes in my machine and load

 

[Andrew Leigh]

Hi

Have you considered using copper foil instead of the litz wire. If it is getting very hot then use a Kapton® film as the interturn insulation or any similar Polyimide film. You must make sure however that the film extends past the side of the foil so that you have some tracking distance.

The average enamelled copper wire copes very well with 200°C so when you say it is getting hot are you worried about the wire failing or the general heat in the enclosure. When looking at your picture the yellow thermosetting tape has discoloured which would indicate that it was getting hot before.




Regards
Andrew

 

[Valence_4]

Did anyone ever wound their own litz wire ? Ok, its not as clean as comercial Litz wire, but for short lenths, i wind my own Litz with very small enameled wires wound together

Litz has better RF performance and is easier to bend than solid copper wire.